If there's one thing most smartphones have in common, it's awful battery life. DIYER Paulie gave his phone a bit more juice by installing a solar panel on the back.

To put this together, you'll need to solder the solar panel's connections to a USB cord, then plug that into your phone. Paulie also cut open the back of his phone and attached the solar cells to the back panel (though we imagine it'd still work if you put a case over it and installed the cells inside that). You can get the solar panels from two cheap landscaping lights, and they can put out about 3V each, which together should be enough to get some extra charge into the phone. It's a perfect little hack for if, say, you're out at the park, eating lunch outside, or otherwise under the sun and want to give your phone a little jolt. Check out the video above to see how it's done.